-- | Functions that return 'String' values containing codes in accordance with:
-- (1) standard ECMA-48 Control Functions for Coded Character Sets (5th edition,
-- 1991); or (2) in the case of 'setTitleCode', the XTerm control sequence.
--
-- The reference used for the codes in this module was
-- <http://en.wikipedia.org/wiki/ANSI_escape_sequences>.
--
-- If module "System.Console.ANSI" is also imported, this module is intended to
-- be imported qualified, to avoid name clashes with functions which return \"\"
-- when Windows ANSI terminal support is emulated. e.g.
--
-- > import qualified System.Console.ANSI.Codes as ANSI
--
module System.Console.ANSI.Codes
    (
      -- * Basic data types
      module System.Console.ANSI.Types

      -- * Cursor movement by character
    , cursorUpCode, cursorDownCode, cursorForwardCode, cursorBackwardCode

      -- * Cursor movement by line
    , cursorUpLineCode, cursorDownLineCode

      -- * Directly changing cursor position
    , setCursorColumnCode, setCursorPositionCode

      -- * Saving, restoring and reporting cursor position
    , saveCursorCode, restoreCursorCode, reportCursorPositionCode

      -- * Clearing parts of the screen
    , clearFromCursorToScreenEndCode, clearFromCursorToScreenBeginningCode
    , clearScreenCode, clearFromCursorToLineEndCode
    , clearFromCursorToLineBeginningCode, clearLineCode

      -- * Scrolling the screen
    , scrollPageUpCode, scrollPageDownCode

      -- * Select Graphic Rendition mode: colors and other whizzy stuff
    , setSGRCode

      -- * Cursor visibilty changes
    , hideCursorCode, showCursorCode

      -- * Changing the title
      -- | Thanks to Brandon S. Allbery and Curt Sampson for pointing me in the
      -- right direction on xterm title setting on haskell-cafe. The "0"
      -- signifies that both the title and "icon" text should be set: i.e. the
      -- text for the window in the Start bar (or similar) as well as that in
      -- the actual window title. This is chosen for consistent behaviour
      -- between Unixes and Windows.
    , setTitleCode

      -- * Utilities
    , colorToCode, csi, sgrToCode
    ) where

import Data.Colour.SRGB (toSRGB24, RGB (..))
import Data.List (intersperse)
import System.Console.ANSI.Types

-- | 'csi' @parameters controlFunction@, where @parameters@ is a list of 'Int',
-- returns the control sequence comprising the control function CONTROL
-- SEQUENCE INTRODUCER (CSI) followed by the parameter(s) (separated by \';\')
-- and ending with the @controlFunction@ character(s) that identifies the
-- control function.
csi :: [Int]  -- ^ List of parameters for the control sequence
    -> String -- ^ Character(s) that identify the control function
    -> String
csi args code = "\ESC[" ++ concat (intersperse ";" (map show args)) ++ code

-- | 'colorToCode' @color@ returns the 0-based index of the color (one of the
-- eight colors in the standard).
colorToCode :: Color -> Int
colorToCode color = case color of
    Black   -> 0
    Red     -> 1
    Green   -> 2
    Yellow  -> 3
    Blue    -> 4
    Magenta -> 5
    Cyan    -> 6
    White   -> 7

-- | 'sgrToCode' @sgr@ returns the parameter of the SELECT GRAPHIC RENDITION
-- (SGR) aspect identified by @sgr@.
sgrToCode :: SGR -- ^ The SGR aspect
          -> [Int]
sgrToCode sgr = case sgr of
    Reset -> [0]
    SetConsoleIntensity intensity -> case intensity of
        BoldIntensity   -> [1]
        FaintIntensity  -> [2]
        NormalIntensity -> [22]
    SetItalicized True  -> [3]
    SetItalicized False -> [23]
    SetUnderlining underlining -> case underlining of
        SingleUnderline -> [4]
        DoubleUnderline -> [21]
        NoUnderline     -> [24]
    SetBlinkSpeed blink_speed -> case blink_speed of
        SlowBlink   -> [5]
        RapidBlink  -> [6]
        NoBlink     -> [25]
    SetVisible False -> [8]
    SetVisible True  -> [28]
    SetSwapForegroundBackground True  -> [7]
    SetSwapForegroundBackground False -> [27]
    SetColor Foreground Dull color  -> [30 + colorToCode color]
    SetColor Foreground Vivid color -> [90 + colorToCode color]
    SetColor Background Dull color  -> [40 + colorToCode color]
    SetColor Background Vivid color -> [100 + colorToCode color]
    SetRGBColor Foreground color -> [38, 2] ++ toRGB color
    SetRGBColor Background color -> [48, 2] ++ toRGB color
  where
    toRGB color = let RGB r g b = toSRGB24 color
                  in  map fromIntegral [r, g, b]

cursorUpCode, cursorDownCode, cursorForwardCode, cursorBackwardCode :: Int -- ^ Number of lines or characters to move
                                                                    -> String
cursorUpCode n = csi [n] "A"
cursorDownCode n = csi [n] "B"
cursorForwardCode n = csi [n] "C"
cursorBackwardCode n = csi [n] "D"

cursorDownLineCode, cursorUpLineCode :: Int -- ^ Number of lines to move
                                     -> String
cursorDownLineCode n = csi [n] "E"
cursorUpLineCode n = csi [n] "F"

setCursorColumnCode :: Int -- ^ 0-based column to move to
                    -> String
setCursorColumnCode n = csi [n + 1] "G"

setCursorPositionCode :: Int -- ^ 0-based row to move to
                      -> Int -- ^ 0-based column to move to
                      -> String
setCursorPositionCode n m = csi [n + 1, m + 1] "H"

saveCursorCode, restoreCursorCode, reportCursorPositionCode :: String
saveCursorCode = "\ESC7"
restoreCursorCode = "\ESC8"
reportCursorPositionCode = csi [] "6n"

clearFromCursorToScreenEndCode, clearFromCursorToScreenBeginningCode, clearScreenCode :: String
clearFromCursorToLineEndCode, clearFromCursorToLineBeginningCode, clearLineCode :: String

clearFromCursorToScreenEndCode = csi [0] "J"
clearFromCursorToScreenBeginningCode = csi [1] "J"
clearScreenCode = csi [2] "J"
clearFromCursorToLineEndCode = csi [0] "K"
clearFromCursorToLineBeginningCode = csi [1] "K"
clearLineCode = csi [2] "K"

scrollPageUpCode, scrollPageDownCode :: Int -- ^ Number of lines to scroll by
                                     -> String
scrollPageUpCode n = csi [n] "S"
scrollPageDownCode n = csi [n] "T"

setSGRCode :: [SGR] -- ^ Commands: these will typically be applied on top of the
                    -- current console SGR mode. An empty list of commands is
                    -- equivalent to the list @[Reset]@. Commands are applied
                    -- left to right.
           -> String
setSGRCode sgrs = csi (concatMap sgrToCode sgrs) "m"

hideCursorCode, showCursorCode :: String
hideCursorCode = csi [] "?25l"
showCursorCode = csi [] "?25h"


-- | XTerm control sequence to set the Icon Name and Window Title.
setTitleCode :: String -- ^ New Icon Name and Window Title
             -> String
setTitleCode title = "\ESC]0;" ++ filter (/= '\007') title ++ "\007"
